xref: /linux/drivers/usb/serial/cp210x.c (revision 6f923a0134d9868a71db19cca1fae551a27b46f5)
1 /*
2  * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
3  *
4  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
5  *
6  *	This program is free software; you can redistribute it and/or
7  *	modify it under the terms of the GNU General Public License version
8  *	2 as published by the Free Software Foundation.
9  *
10  * Support to set flow control line levels using TIOCMGET and TIOCMSET
11  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
12  * control thanks to Munir Nassar nassarmu@real-time.com
13  *
14  */
15 
16 #include <linux/kernel.h>
17 #include <linux/errno.h>
18 #include <linux/slab.h>
19 #include <linux/tty.h>
20 #include <linux/tty_flip.h>
21 #include <linux/module.h>
22 #include <linux/moduleparam.h>
23 #include <linux/usb.h>
24 #include <linux/uaccess.h>
25 #include <linux/usb/serial.h>
26 
27 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
28 
29 /*
30  * Function Prototypes
31  */
32 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
33 static void cp210x_close(struct usb_serial_port *);
34 static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *);
35 static void cp210x_get_termios_port(struct usb_serial_port *port,
36 	unsigned int *cflagp, unsigned int *baudp);
37 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
38 							struct ktermios *);
39 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
40 							struct ktermios*);
41 static bool cp210x_tx_empty(struct usb_serial_port *port);
42 static int cp210x_tiocmget(struct tty_struct *);
43 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
44 static int cp210x_tiocmset_port(struct usb_serial_port *port,
45 		unsigned int, unsigned int);
46 static void cp210x_break_ctl(struct tty_struct *, int);
47 static int cp210x_port_probe(struct usb_serial_port *);
48 static int cp210x_port_remove(struct usb_serial_port *);
49 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
50 
51 static const struct usb_device_id id_table[] = {
52 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
53 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
54 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
55 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
56 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
57 	{ USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
58 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
59 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
60 	{ USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
61 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
62 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
63 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
64 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
65 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
66 	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
67 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
68 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
69 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
70 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
71 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
72 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
73 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
74 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
75 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
76 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
77 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
78 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
79 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
80 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
81 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
82 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
83 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
84 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
85 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
86 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
87 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
88 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
89 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
90 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
91 	{ USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
92 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
93 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
94 	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
95 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
96 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
97 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
98 	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
99 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
100 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
101 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
102 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
103 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
104 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
105 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
106 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
107 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
108 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
109 	{ USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
110 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
111 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
112 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
113 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
114 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
115 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
116 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
117 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
118 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
119 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
120 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
121 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
122 	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
123 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
124 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
125 	{ USB_DEVICE(0x10C4, 0x8856) },	/* CEL EM357 ZigBee USB Stick - LR */
126 	{ USB_DEVICE(0x10C4, 0x8857) },	/* CEL EM357 ZigBee USB Stick */
127 	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
128 	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
129 	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
130 	{ USB_DEVICE(0x10C4, 0x8977) },	/* CEL MeshWorks DevKit Device */
131 	{ USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
132 	{ USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
133 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
134 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
135 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
136 	{ USB_DEVICE(0x10C4, 0xEA80) }, /* Silicon Labs factory default */
137 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
138 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
139 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
140 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
141 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
142 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
143 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
144 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
145 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
146 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
147 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
148 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
149 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
150 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
151 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
152 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
153 	{ USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
154 	{ USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
155 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
156 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
157 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
158 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
159 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
160 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
161 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
162 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
163 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
164 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
165 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
166 	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
167 	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
168 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
169 	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
170 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
171 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
172 	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
173 	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
174 	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
175 	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
176 	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
177 	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
178 	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
179 	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
180 	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
181 	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
182 	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
183 	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
184 	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
185 	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
186 	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
187 	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
188 	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
189 	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
190 	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
191 	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
192 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
193 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
194 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
195 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
196 	{ } /* Terminating Entry */
197 };
198 
199 MODULE_DEVICE_TABLE(usb, id_table);
200 
201 struct cp210x_port_private {
202 	__u8			bInterfaceNumber;
203 	bool			has_swapped_line_ctl;
204 };
205 
206 static struct usb_serial_driver cp210x_device = {
207 	.driver = {
208 		.owner =	THIS_MODULE,
209 		.name =		"cp210x",
210 	},
211 	.id_table		= id_table,
212 	.num_ports		= 1,
213 	.bulk_in_size		= 256,
214 	.bulk_out_size		= 256,
215 	.open			= cp210x_open,
216 	.close			= cp210x_close,
217 	.break_ctl		= cp210x_break_ctl,
218 	.set_termios		= cp210x_set_termios,
219 	.tx_empty		= cp210x_tx_empty,
220 	.tiocmget		= cp210x_tiocmget,
221 	.tiocmset		= cp210x_tiocmset,
222 	.port_probe		= cp210x_port_probe,
223 	.port_remove		= cp210x_port_remove,
224 	.dtr_rts		= cp210x_dtr_rts
225 };
226 
227 static struct usb_serial_driver * const serial_drivers[] = {
228 	&cp210x_device, NULL
229 };
230 
231 /* Config request types */
232 #define REQTYPE_HOST_TO_INTERFACE	0x41
233 #define REQTYPE_INTERFACE_TO_HOST	0xc1
234 #define REQTYPE_HOST_TO_DEVICE	0x40
235 #define REQTYPE_DEVICE_TO_HOST	0xc0
236 
237 /* Config request codes */
238 #define CP210X_IFC_ENABLE	0x00
239 #define CP210X_SET_BAUDDIV	0x01
240 #define CP210X_GET_BAUDDIV	0x02
241 #define CP210X_SET_LINE_CTL	0x03
242 #define CP210X_GET_LINE_CTL	0x04
243 #define CP210X_SET_BREAK	0x05
244 #define CP210X_IMM_CHAR		0x06
245 #define CP210X_SET_MHS		0x07
246 #define CP210X_GET_MDMSTS	0x08
247 #define CP210X_SET_XON		0x09
248 #define CP210X_SET_XOFF		0x0A
249 #define CP210X_SET_EVENTMASK	0x0B
250 #define CP210X_GET_EVENTMASK	0x0C
251 #define CP210X_SET_CHAR		0x0D
252 #define CP210X_GET_CHARS	0x0E
253 #define CP210X_GET_PROPS	0x0F
254 #define CP210X_GET_COMM_STATUS	0x10
255 #define CP210X_RESET		0x11
256 #define CP210X_PURGE		0x12
257 #define CP210X_SET_FLOW		0x13
258 #define CP210X_GET_FLOW		0x14
259 #define CP210X_EMBED_EVENTS	0x15
260 #define CP210X_GET_EVENTSTATE	0x16
261 #define CP210X_SET_CHARS	0x19
262 #define CP210X_GET_BAUDRATE	0x1D
263 #define CP210X_SET_BAUDRATE	0x1E
264 
265 /* CP210X_IFC_ENABLE */
266 #define UART_ENABLE		0x0001
267 #define UART_DISABLE		0x0000
268 
269 /* CP210X_(SET|GET)_BAUDDIV */
270 #define BAUD_RATE_GEN_FREQ	0x384000
271 
272 /* CP210X_(SET|GET)_LINE_CTL */
273 #define BITS_DATA_MASK		0X0f00
274 #define BITS_DATA_5		0X0500
275 #define BITS_DATA_6		0X0600
276 #define BITS_DATA_7		0X0700
277 #define BITS_DATA_8		0X0800
278 #define BITS_DATA_9		0X0900
279 
280 #define BITS_PARITY_MASK	0x00f0
281 #define BITS_PARITY_NONE	0x0000
282 #define BITS_PARITY_ODD		0x0010
283 #define BITS_PARITY_EVEN	0x0020
284 #define BITS_PARITY_MARK	0x0030
285 #define BITS_PARITY_SPACE	0x0040
286 
287 #define BITS_STOP_MASK		0x000f
288 #define BITS_STOP_1		0x0000
289 #define BITS_STOP_1_5		0x0001
290 #define BITS_STOP_2		0x0002
291 
292 /* CP210X_SET_BREAK */
293 #define BREAK_ON		0x0001
294 #define BREAK_OFF		0x0000
295 
296 /* CP210X_(SET_MHS|GET_MDMSTS) */
297 #define CONTROL_DTR		0x0001
298 #define CONTROL_RTS		0x0002
299 #define CONTROL_CTS		0x0010
300 #define CONTROL_DSR		0x0020
301 #define CONTROL_RING		0x0040
302 #define CONTROL_DCD		0x0080
303 #define CONTROL_WRITE_DTR	0x0100
304 #define CONTROL_WRITE_RTS	0x0200
305 
306 /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
307 struct cp210x_comm_status {
308 	__le32   ulErrors;
309 	__le32   ulHoldReasons;
310 	__le32   ulAmountInInQueue;
311 	__le32   ulAmountInOutQueue;
312 	u8       bEofReceived;
313 	u8       bWaitForImmediate;
314 	u8       bReserved;
315 } __packed;
316 
317 /*
318  * CP210X_PURGE - 16 bits passed in wValue of USB request.
319  * SiLabs app note AN571 gives a strange description of the 4 bits:
320  * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
321  * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
322  */
323 #define PURGE_ALL		0x000f
324 
325 /*
326  * cp210x_get_config
327  * Reads from the CP210x configuration registers
328  * 'size' is specified in bytes.
329  * 'data' is a pointer to a pre-allocated array of integers large
330  * enough to hold 'size' bytes (with 4 bytes to each integer)
331  */
332 static int cp210x_get_config(struct usb_serial_port *port, u8 request,
333 		unsigned int *data, int size)
334 {
335 	struct usb_serial *serial = port->serial;
336 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
337 	__le32 *buf;
338 	int result, i, length;
339 
340 	/* Number of integers required to contain the array */
341 	length = (((size - 1) | 3) + 1) / 4;
342 
343 	buf = kcalloc(length, sizeof(__le32), GFP_KERNEL);
344 	if (!buf)
345 		return -ENOMEM;
346 
347 	/* Issue the request, attempting to read 'size' bytes */
348 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
349 				request, REQTYPE_INTERFACE_TO_HOST, 0x0000,
350 				port_priv->bInterfaceNumber, buf, size,
351 				USB_CTRL_GET_TIMEOUT);
352 
353 	/* Convert data into an array of integers */
354 	for (i = 0; i < length; i++)
355 		data[i] = le32_to_cpu(buf[i]);
356 
357 	kfree(buf);
358 
359 	if (result != size) {
360 		dev_dbg(&port->dev, "%s - Unable to send config request, request=0x%x size=%d result=%d\n",
361 			__func__, request, size, result);
362 		if (result > 0)
363 			result = -EPROTO;
364 
365 		return result;
366 	}
367 
368 	return 0;
369 }
370 
371 /*
372  * cp210x_set_config
373  * Writes to the CP210x configuration registers
374  * Values less than 16 bits wide are sent directly
375  * 'size' is specified in bytes.
376  */
377 static int cp210x_set_config(struct usb_serial_port *port, u8 request,
378 		unsigned int *data, int size)
379 {
380 	struct usb_serial *serial = port->serial;
381 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
382 	__le32 *buf;
383 	int result, i, length;
384 
385 	/* Number of integers required to contain the array */
386 	length = (((size - 1) | 3) + 1) / 4;
387 
388 	buf = kmalloc(length * sizeof(__le32), GFP_KERNEL);
389 	if (!buf)
390 		return -ENOMEM;
391 
392 	/* Array of integers into bytes */
393 	for (i = 0; i < length; i++)
394 		buf[i] = cpu_to_le32(data[i]);
395 
396 	if (size > 2) {
397 		result = usb_control_msg(serial->dev,
398 				usb_sndctrlpipe(serial->dev, 0),
399 				request, REQTYPE_HOST_TO_INTERFACE, 0x0000,
400 				port_priv->bInterfaceNumber, buf, size,
401 				USB_CTRL_SET_TIMEOUT);
402 	} else {
403 		result = usb_control_msg(serial->dev,
404 				usb_sndctrlpipe(serial->dev, 0),
405 				request, REQTYPE_HOST_TO_INTERFACE, data[0],
406 				port_priv->bInterfaceNumber, NULL, 0,
407 				USB_CTRL_SET_TIMEOUT);
408 	}
409 
410 	kfree(buf);
411 
412 	if ((size > 2 && result != size) || result < 0) {
413 		dev_dbg(&port->dev, "%s - Unable to send request, request=0x%x size=%d result=%d\n",
414 			__func__, request, size, result);
415 		if (result > 0)
416 			result = -EPROTO;
417 
418 		return result;
419 	}
420 
421 	return 0;
422 }
423 
424 /*
425  * cp210x_set_config_single
426  * Convenience function for calling cp210x_set_config on single data values
427  * without requiring an integer pointer
428  */
429 static inline int cp210x_set_config_single(struct usb_serial_port *port,
430 		u8 request, unsigned int data)
431 {
432 	return cp210x_set_config(port, request, &data, 2);
433 }
434 
435 /*
436  * Detect CP2108 GET_LINE_CTL bug and activate workaround.
437  * Write a known good value 0x800, read it back.
438  * If it comes back swapped the bug is detected.
439  * Preserve the original register value.
440  */
441 static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
442 {
443 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
444 	unsigned int line_ctl_save;
445 	unsigned int line_ctl_test;
446 	int err;
447 
448 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_save, 2);
449 	if (err)
450 		return err;
451 
452 	line_ctl_test = 0x800;
453 	err = cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_test, 2);
454 	if (err)
455 		return err;
456 
457 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, &line_ctl_test, 2);
458 	if (err)
459 		return err;
460 
461 	if (line_ctl_test == 8) {
462 		port_priv->has_swapped_line_ctl = true;
463 		line_ctl_save = swab16((u16)line_ctl_save);
464 	}
465 
466 	return cp210x_set_config(port, CP210X_SET_LINE_CTL, &line_ctl_save, 2);
467 }
468 
469 /*
470  * Must always be called instead of cp210x_get_config(CP210X_GET_LINE_CTL)
471  * to workaround cp2108 bug and get correct value.
472  */
473 static int cp210x_get_line_ctl(struct usb_serial_port *port, unsigned int *ctl)
474 {
475 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
476 	int err;
477 
478 	err = cp210x_get_config(port, CP210X_GET_LINE_CTL, ctl, 2);
479 	if (err)
480 		return err;
481 
482 	/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
483 	if (port_priv->has_swapped_line_ctl)
484 		*ctl = swab16((u16)(*ctl));
485 
486 	return 0;
487 }
488 
489 /*
490  * cp210x_quantise_baudrate
491  * Quantises the baud rate as per AN205 Table 1
492  */
493 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
494 {
495 	if (baud <= 300)
496 		baud = 300;
497 	else if (baud <= 600)      baud = 600;
498 	else if (baud <= 1200)     baud = 1200;
499 	else if (baud <= 1800)     baud = 1800;
500 	else if (baud <= 2400)     baud = 2400;
501 	else if (baud <= 4000)     baud = 4000;
502 	else if (baud <= 4803)     baud = 4800;
503 	else if (baud <= 7207)     baud = 7200;
504 	else if (baud <= 9612)     baud = 9600;
505 	else if (baud <= 14428)    baud = 14400;
506 	else if (baud <= 16062)    baud = 16000;
507 	else if (baud <= 19250)    baud = 19200;
508 	else if (baud <= 28912)    baud = 28800;
509 	else if (baud <= 38601)    baud = 38400;
510 	else if (baud <= 51558)    baud = 51200;
511 	else if (baud <= 56280)    baud = 56000;
512 	else if (baud <= 58053)    baud = 57600;
513 	else if (baud <= 64111)    baud = 64000;
514 	else if (baud <= 77608)    baud = 76800;
515 	else if (baud <= 117028)   baud = 115200;
516 	else if (baud <= 129347)   baud = 128000;
517 	else if (baud <= 156868)   baud = 153600;
518 	else if (baud <= 237832)   baud = 230400;
519 	else if (baud <= 254234)   baud = 250000;
520 	else if (baud <= 273066)   baud = 256000;
521 	else if (baud <= 491520)   baud = 460800;
522 	else if (baud <= 567138)   baud = 500000;
523 	else if (baud <= 670254)   baud = 576000;
524 	else if (baud < 1000000)
525 		baud = 921600;
526 	else if (baud > 2000000)
527 		baud = 2000000;
528 	return baud;
529 }
530 
531 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
532 {
533 	int result;
534 
535 	result = cp210x_set_config_single(port, CP210X_IFC_ENABLE,
536 								UART_ENABLE);
537 	if (result) {
538 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
539 		return result;
540 	}
541 
542 	/* Configure the termios structure */
543 	cp210x_get_termios(tty, port);
544 
545 	/* The baud rate must be initialised on cp2104 */
546 	if (tty)
547 		cp210x_change_speed(tty, port, NULL);
548 
549 	return usb_serial_generic_open(tty, port);
550 }
551 
552 static void cp210x_close(struct usb_serial_port *port)
553 {
554 	unsigned int purge_ctl;
555 
556 	usb_serial_generic_close(port);
557 
558 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
559 	purge_ctl = PURGE_ALL;
560 	cp210x_set_config(port, CP210X_PURGE, &purge_ctl, 2);
561 
562 	cp210x_set_config_single(port, CP210X_IFC_ENABLE, UART_DISABLE);
563 }
564 
565 /*
566  * Read how many bytes are waiting in the TX queue.
567  */
568 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
569 		u32 *count)
570 {
571 	struct usb_serial *serial = port->serial;
572 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
573 	struct cp210x_comm_status *sts;
574 	int result;
575 
576 	sts = kmalloc(sizeof(*sts), GFP_KERNEL);
577 	if (!sts)
578 		return -ENOMEM;
579 
580 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
581 			CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
582 			0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
583 			USB_CTRL_GET_TIMEOUT);
584 	if (result == sizeof(*sts)) {
585 		*count = le32_to_cpu(sts->ulAmountInOutQueue);
586 		result = 0;
587 	} else {
588 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
589 		if (result >= 0)
590 			result = -EPROTO;
591 	}
592 
593 	kfree(sts);
594 
595 	return result;
596 }
597 
598 static bool cp210x_tx_empty(struct usb_serial_port *port)
599 {
600 	int err;
601 	u32 count;
602 
603 	err = cp210x_get_tx_queue_byte_count(port, &count);
604 	if (err)
605 		return true;
606 
607 	return !count;
608 }
609 
610 /*
611  * cp210x_get_termios
612  * Reads the baud rate, data bits, parity, stop bits and flow control mode
613  * from the device, corrects any unsupported values, and configures the
614  * termios structure to reflect the state of the device
615  */
616 static void cp210x_get_termios(struct tty_struct *tty,
617 	struct usb_serial_port *port)
618 {
619 	unsigned int baud;
620 
621 	if (tty) {
622 		cp210x_get_termios_port(tty->driver_data,
623 			&tty->termios.c_cflag, &baud);
624 		tty_encode_baud_rate(tty, baud, baud);
625 	} else {
626 		unsigned int cflag;
627 		cflag = 0;
628 		cp210x_get_termios_port(port, &cflag, &baud);
629 	}
630 }
631 
632 /*
633  * cp210x_get_termios_port
634  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
635  */
636 static void cp210x_get_termios_port(struct usb_serial_port *port,
637 	unsigned int *cflagp, unsigned int *baudp)
638 {
639 	struct device *dev = &port->dev;
640 	unsigned int cflag, modem_ctl[4];
641 	unsigned int baud;
642 	unsigned int bits;
643 
644 	cp210x_get_config(port, CP210X_GET_BAUDRATE, &baud, 4);
645 
646 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
647 	*baudp = baud;
648 
649 	cflag = *cflagp;
650 
651 	cp210x_get_line_ctl(port, &bits);
652 	cflag &= ~CSIZE;
653 	switch (bits & BITS_DATA_MASK) {
654 	case BITS_DATA_5:
655 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
656 		cflag |= CS5;
657 		break;
658 	case BITS_DATA_6:
659 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
660 		cflag |= CS6;
661 		break;
662 	case BITS_DATA_7:
663 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
664 		cflag |= CS7;
665 		break;
666 	case BITS_DATA_8:
667 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
668 		cflag |= CS8;
669 		break;
670 	case BITS_DATA_9:
671 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
672 		cflag |= CS8;
673 		bits &= ~BITS_DATA_MASK;
674 		bits |= BITS_DATA_8;
675 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
676 		break;
677 	default:
678 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
679 		cflag |= CS8;
680 		bits &= ~BITS_DATA_MASK;
681 		bits |= BITS_DATA_8;
682 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
683 		break;
684 	}
685 
686 	switch (bits & BITS_PARITY_MASK) {
687 	case BITS_PARITY_NONE:
688 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
689 		cflag &= ~PARENB;
690 		break;
691 	case BITS_PARITY_ODD:
692 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
693 		cflag |= (PARENB|PARODD);
694 		break;
695 	case BITS_PARITY_EVEN:
696 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
697 		cflag &= ~PARODD;
698 		cflag |= PARENB;
699 		break;
700 	case BITS_PARITY_MARK:
701 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
702 		cflag |= (PARENB|PARODD|CMSPAR);
703 		break;
704 	case BITS_PARITY_SPACE:
705 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
706 		cflag &= ~PARODD;
707 		cflag |= (PARENB|CMSPAR);
708 		break;
709 	default:
710 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
711 		cflag &= ~PARENB;
712 		bits &= ~BITS_PARITY_MASK;
713 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
714 		break;
715 	}
716 
717 	cflag &= ~CSTOPB;
718 	switch (bits & BITS_STOP_MASK) {
719 	case BITS_STOP_1:
720 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
721 		break;
722 	case BITS_STOP_1_5:
723 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
724 		bits &= ~BITS_STOP_MASK;
725 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
726 		break;
727 	case BITS_STOP_2:
728 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
729 		cflag |= CSTOPB;
730 		break;
731 	default:
732 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
733 		bits &= ~BITS_STOP_MASK;
734 		cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2);
735 		break;
736 	}
737 
738 	cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
739 	if (modem_ctl[0] & 0x0008) {
740 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
741 		cflag |= CRTSCTS;
742 	} else {
743 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
744 		cflag &= ~CRTSCTS;
745 	}
746 
747 	*cflagp = cflag;
748 }
749 
750 /*
751  * CP2101 supports the following baud rates:
752  *
753  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
754  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
755  *
756  * CP2102 and CP2103 support the following additional rates:
757  *
758  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
759  *	576000
760  *
761  * The device will map a requested rate to a supported one, but the result
762  * of requests for rates greater than 1053257 is undefined (see AN205).
763  *
764  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
765  * respectively, with an error less than 1%. The actual rates are determined
766  * by
767  *
768  *	div = round(freq / (2 x prescale x request))
769  *	actual = freq / (2 x prescale x div)
770  *
771  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
772  * or 1 otherwise.
773  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
774  * otherwise.
775  */
776 static void cp210x_change_speed(struct tty_struct *tty,
777 		struct usb_serial_port *port, struct ktermios *old_termios)
778 {
779 	u32 baud;
780 
781 	baud = tty->termios.c_ospeed;
782 
783 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
784 	 * or to an arbitrary rate in [1M,2M].
785 	 *
786 	 * NOTE: B0 is not implemented.
787 	 */
788 	baud = cp210x_quantise_baudrate(baud);
789 
790 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
791 	if (cp210x_set_config(port, CP210X_SET_BAUDRATE, &baud,
792 							sizeof(baud))) {
793 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
794 		if (old_termios)
795 			baud = old_termios->c_ospeed;
796 		else
797 			baud = 9600;
798 	}
799 
800 	tty_encode_baud_rate(tty, baud, baud);
801 }
802 
803 static void cp210x_set_termios(struct tty_struct *tty,
804 		struct usb_serial_port *port, struct ktermios *old_termios)
805 {
806 	struct device *dev = &port->dev;
807 	unsigned int cflag, old_cflag;
808 	unsigned int bits;
809 	unsigned int modem_ctl[4];
810 
811 	cflag = tty->termios.c_cflag;
812 	old_cflag = old_termios->c_cflag;
813 
814 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
815 		cp210x_change_speed(tty, port, old_termios);
816 
817 	/* If the number of data bits is to be updated */
818 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
819 		cp210x_get_line_ctl(port, &bits);
820 		bits &= ~BITS_DATA_MASK;
821 		switch (cflag & CSIZE) {
822 		case CS5:
823 			bits |= BITS_DATA_5;
824 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
825 			break;
826 		case CS6:
827 			bits |= BITS_DATA_6;
828 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
829 			break;
830 		case CS7:
831 			bits |= BITS_DATA_7;
832 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
833 			break;
834 		case CS8:
835 			bits |= BITS_DATA_8;
836 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
837 			break;
838 		/*case CS9:
839 			bits |= BITS_DATA_9;
840 			dev_dbg(dev, "%s - data bits = 9\n", __func__);
841 			break;*/
842 		default:
843 			dev_dbg(dev, "cp210x driver does not support the number of bits requested, using 8 bit mode\n");
844 			bits |= BITS_DATA_8;
845 			break;
846 		}
847 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
848 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
849 	}
850 
851 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
852 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
853 		cp210x_get_line_ctl(port, &bits);
854 		bits &= ~BITS_PARITY_MASK;
855 		if (cflag & PARENB) {
856 			if (cflag & CMSPAR) {
857 				if (cflag & PARODD) {
858 					bits |= BITS_PARITY_MARK;
859 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
860 				} else {
861 					bits |= BITS_PARITY_SPACE;
862 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
863 				}
864 			} else {
865 				if (cflag & PARODD) {
866 					bits |= BITS_PARITY_ODD;
867 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
868 				} else {
869 					bits |= BITS_PARITY_EVEN;
870 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
871 				}
872 			}
873 		}
874 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
875 			dev_dbg(dev, "Parity mode not supported by device\n");
876 	}
877 
878 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
879 		cp210x_get_line_ctl(port, &bits);
880 		bits &= ~BITS_STOP_MASK;
881 		if (cflag & CSTOPB) {
882 			bits |= BITS_STOP_2;
883 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
884 		} else {
885 			bits |= BITS_STOP_1;
886 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
887 		}
888 		if (cp210x_set_config(port, CP210X_SET_LINE_CTL, &bits, 2))
889 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
890 	}
891 
892 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
893 		cp210x_get_config(port, CP210X_GET_FLOW, modem_ctl, 16);
894 		dev_dbg(dev, "%s - read modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
895 			__func__, modem_ctl[0], modem_ctl[1],
896 			modem_ctl[2], modem_ctl[3]);
897 
898 		if (cflag & CRTSCTS) {
899 			modem_ctl[0] &= ~0x7B;
900 			modem_ctl[0] |= 0x09;
901 			modem_ctl[1] = 0x80;
902 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
903 		} else {
904 			modem_ctl[0] &= ~0x7B;
905 			modem_ctl[0] |= 0x01;
906 			modem_ctl[1] |= 0x40;
907 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
908 		}
909 
910 		dev_dbg(dev, "%s - write modem controls = 0x%.4x 0x%.4x 0x%.4x 0x%.4x\n",
911 			__func__, modem_ctl[0], modem_ctl[1],
912 			modem_ctl[2], modem_ctl[3]);
913 		cp210x_set_config(port, CP210X_SET_FLOW, modem_ctl, 16);
914 	}
915 
916 }
917 
918 static int cp210x_tiocmset(struct tty_struct *tty,
919 		unsigned int set, unsigned int clear)
920 {
921 	struct usb_serial_port *port = tty->driver_data;
922 	return cp210x_tiocmset_port(port, set, clear);
923 }
924 
925 static int cp210x_tiocmset_port(struct usb_serial_port *port,
926 		unsigned int set, unsigned int clear)
927 {
928 	unsigned int control = 0;
929 
930 	if (set & TIOCM_RTS) {
931 		control |= CONTROL_RTS;
932 		control |= CONTROL_WRITE_RTS;
933 	}
934 	if (set & TIOCM_DTR) {
935 		control |= CONTROL_DTR;
936 		control |= CONTROL_WRITE_DTR;
937 	}
938 	if (clear & TIOCM_RTS) {
939 		control &= ~CONTROL_RTS;
940 		control |= CONTROL_WRITE_RTS;
941 	}
942 	if (clear & TIOCM_DTR) {
943 		control &= ~CONTROL_DTR;
944 		control |= CONTROL_WRITE_DTR;
945 	}
946 
947 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
948 
949 	return cp210x_set_config(port, CP210X_SET_MHS, &control, 2);
950 }
951 
952 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
953 {
954 	if (on)
955 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
956 	else
957 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
958 }
959 
960 static int cp210x_tiocmget(struct tty_struct *tty)
961 {
962 	struct usb_serial_port *port = tty->driver_data;
963 	unsigned int control;
964 	int result;
965 
966 	cp210x_get_config(port, CP210X_GET_MDMSTS, &control, 1);
967 
968 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
969 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
970 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
971 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
972 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
973 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
974 
975 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
976 
977 	return result;
978 }
979 
980 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
981 {
982 	struct usb_serial_port *port = tty->driver_data;
983 	unsigned int state;
984 
985 	if (break_state == 0)
986 		state = BREAK_OFF;
987 	else
988 		state = BREAK_ON;
989 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
990 		state == BREAK_OFF ? "off" : "on");
991 	cp210x_set_config(port, CP210X_SET_BREAK, &state, 2);
992 }
993 
994 static int cp210x_port_probe(struct usb_serial_port *port)
995 {
996 	struct usb_serial *serial = port->serial;
997 	struct usb_host_interface *cur_altsetting;
998 	struct cp210x_port_private *port_priv;
999 	int ret;
1000 
1001 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1002 	if (!port_priv)
1003 		return -ENOMEM;
1004 
1005 	cur_altsetting = serial->interface->cur_altsetting;
1006 	port_priv->bInterfaceNumber = cur_altsetting->desc.bInterfaceNumber;
1007 
1008 	usb_set_serial_port_data(port, port_priv);
1009 
1010 	ret = cp210x_detect_swapped_line_ctl(port);
1011 	if (ret) {
1012 		kfree(port_priv);
1013 		return ret;
1014 	}
1015 
1016 	return 0;
1017 }
1018 
1019 static int cp210x_port_remove(struct usb_serial_port *port)
1020 {
1021 	struct cp210x_port_private *port_priv;
1022 
1023 	port_priv = usb_get_serial_port_data(port);
1024 	kfree(port_priv);
1025 
1026 	return 0;
1027 }
1028 
1029 module_usb_serial_driver(serial_drivers, id_table);
1030 
1031 MODULE_DESCRIPTION(DRIVER_DESC);
1032 MODULE_LICENSE("GPL");
1033